From 6ec830ac0cc3b9d234a3f67d87da0c304b42246c Mon Sep 17 00:00:00 2001 From: Santhosh Behara Date: Mon, 5 Jun 2017 15:21:22 -0700 Subject: [PATCH] mm-video-v4l2: venc: Protect buffer from being freed while accessing Output buffer (in use-buffer mode) has an internal backup ion buffer. The contents of this buffer are deep-copied in client's buffer in the context of VideoEncCallBackThread; while this buffer can be freed in the client thread's context. Check the allocation bitmask before attempting to copy and synchronize these operations by holding a lock Fixes bug 36130225 Security Vulnerability - Heap use after free in libOmxVenc CRs-Fixed: 2053101 Author: Praveen Chavan Change-Id: I6141e81d7dbd50bc3601c8df066fd8cbd06b4e0b --- msm8998/mm-video-v4l2/vidc/venc/inc/omx_video_base.h | 1 + msm8998/mm-video-v4l2/vidc/venc/src/omx_video_base.cpp | 6 ++++++ .../mm-video-v4l2/vidc/venc/src/omx_video_encoder.cpp | 10 +++++++++- 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/msm8998/mm-video-v4l2/vidc/venc/inc/omx_video_base.h b/msm8998/mm-video-v4l2/vidc/venc/inc/omx_video_base.h index b2e21afa..7810d5aa 100644 --- a/msm8998/mm-video-v4l2/vidc/venc/inc/omx_video_base.h +++ b/msm8998/mm-video-v4l2/vidc/venc/inc/omx_video_base.h @@ -683,6 +683,7 @@ class omx_video: public qc_omx_component omx_cmd_queue m_opq_meta_q; omx_cmd_queue m_opq_pmem_q; OMX_BUFFERHEADERTYPE meta_buffer_hdr[MAX_NUM_INPUT_BUFFERS]; + pthread_mutex_t m_buf_lock; bool input_flush_progress; bool output_flush_progress; diff --git a/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_base.cpp b/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_base.cpp index 7563ae38..a378a337 100644 --- a/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_base.cpp +++ b/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_base.cpp @@ -328,6 +328,8 @@ omx_video::omx_video(): property_get("ro.board.platform", platform_name, "0"); strlcpy(m_platform, platform_name, sizeof(m_platform)); #endif + + pthread_mutex_init(&m_buf_lock, NULL); } @@ -369,6 +371,8 @@ omx_video::~omx_video() sem_destroy(&m_cmd_lock); DEBUG_PRINT_HIGH("m_etb_count = %" PRIu64 ", m_fbd_count = %" PRIu64, m_etb_count, m_fbd_count); + + pthread_mutex_destroy(&m_buf_lock); DEBUG_PRINT_HIGH("omx_video: Destructor exit"); DEBUG_PRINT_HIGH("Exiting OMX Video Encoder ..."); } @@ -2725,6 +2729,7 @@ OMX_ERRORTYPE omx_video::use_output_buffer( return OMX_ErrorBadParameter; } + auto_lock l(m_buf_lock); if (!m_out_mem_ptr) { output_use_buffer = true; int nBufHdrSize = 0; @@ -3655,6 +3660,7 @@ OMX_ERRORTYPE omx_video::free_buffer(OMX_IN OMX_HANDLETYPE hComp, nPortIndex, (unsigned int)m_sOutPortDef.nBufferCountActual); if (nPortIndex < m_sOutPortDef.nBufferCountActual && BITMASK_PRESENT(&m_out_bm_count, nPortIndex)) { + auto_lock l(m_buf_lock); // Clear the bit associated with it. BITMASK_CLEAR(&m_out_bm_count,nPortIndex); m_sOutPortDef.bPopulated = OMX_FALSE; diff --git a/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_encoder.cpp b/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_encoder.cpp index d5ac1d9b..cf83159a 100644 --- a/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_encoder.cpp +++ b/msm8998/mm-video-v4l2/vidc/venc/src/omx_video_encoder.cpp @@ -2593,10 +2593,17 @@ int omx_venc::async_message_process (void *context, void* message) OMX_COMPONENT_GENERATE_EBD); break; case VEN_MSG_OUTPUT_BUFFER_DONE: + { omxhdr = (OMX_BUFFERHEADERTYPE*)m_sVenc_msg->buf.clientdata; + OMX_U32 bufIndex = (OMX_U32)(omxhdr - omx->m_out_mem_ptr); if ( (omxhdr != NULL) && - ((OMX_U32)(omxhdr - omx->m_out_mem_ptr) < omx->m_sOutPortDef.nBufferCountActual)) { + (bufIndex < omx->m_sOutPortDef.nBufferCountActual)) { + auto_lock l(omx->m_buf_lock); + if (BITMASK_ABSENT(&(omx->m_out_bm_count), bufIndex)) { + DEBUG_PRINT_ERROR("Recieved FBD for buffer that is already freed !"); + break; + } if (!omx->is_secure_session() && (m_sVenc_msg->buf.len <= omxhdr->nAllocLen)) { omxhdr->nFilledLen = m_sVenc_msg->buf.len; omxhdr->nOffset = m_sVenc_msg->buf.offset; @@ -2630,6 +2637,7 @@ int omx_venc::async_message_process (void *context, void* message) omx->post_event ((unsigned long)omxhdr,m_sVenc_msg->statuscode, OMX_COMPONENT_GENERATE_FBD); break; + } case VEN_MSG_NEED_OUTPUT_BUFFER: //TBD what action needs to be done here?? break;